Lutein production by microalgae using corn starch wastewater pretreated with rapid enzymatic hydrolysis

Abstract

The main purpose of this study was to explore the pretreatment process of corn starch wastewater (CSW) and engineered microalgae cultivation strategy to improve the nutrient recovery from wastewater and the yield of microalgae lutein. One-stage enzymatic hydrolysis utilizing α-amylase and glucoamylase simultaneously was established to efficiently harvest a maximum concentration of reducing sugar content of 7.26 g/L from CSW in 50 min. Lutein yield of 10.96 mg/L was obtained under 24 h continuous illumination with 2200 Lux light intensity. Furthermore, a cyclic feeding cultivation strategy was developed to improve lutein accumulation and COD removal up to 25.9 mg/L and 50.7%, respectively, after three cultivation cycles. Lutein yield of 14.86 mg/L and COD removal efficiency of 73.2% was achieved with further implementation in actual wastewater. This work provided a new perspective in developing the potential of cultivating microalgae with corn starch wastewater to produce high-value lutein.